1. Field of the Invention
Present invention relates generally to monitors and displays used in information handling systems. More specifically, the present invention provides an improved method and apparatus for controlling the brightness, color and contrast in cathode ray tube monitors used in information handling systems.
2. Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
One of the most important components of an information handling system is the video display, which is the principal user interface for both text and graphics. In recent years there has been a significant increase in the number of applications that require a video display capable of providing one or more enhanced viewing areas for displaying specialized applications. Examples of applications using enhanced viewing areas on a video display include: DVD movies, monitor/computer control functions, and sRGB display areas for e-commerce transactions.
There are numerous display technologies that have been introduced in recent years, including liquid crystal displays (LCDs), plasma displays, electroluminescent displays (EL) and light emitting diode (LED) displays. Despite the advances in the afore-mentioned technologies, the cathode ray tube (CRT) remains as one of the most common components for providing video displays in information handling systems. CRTs are capable of offering better contrast, luminance and resolution than any other display technology at a comparable price.
Prior art methods for providing an enhanced viewing area in a CRT involve adding signals from an enhanced video circuit to the signals driving the RGB cathodes of the CRT. This design tends to result in an enhanced viewing area that has a smeared or lower quality video image.